The present invention relates to a device for feeding book blocks, books or similar printed products, in step with the working cycle, to a subsequent processing machine
In industrial book production the various processing machines are frequently interconnected to form assembly lines. On the conveyance paths between the machines, the printed products are usually conveyed in no particular order. In order to achieve feeding of the printed products, in step with the working cycle, to a subsequent processing machine, these products must first be transferred to the infeed system separately and then in a manner synchronous with the cycle. From the state of the art, infeed conveyors are known which comprise a continuous-drive accumulating conveyor with an arrestor arranged at the downstream end of the accumulating conveyor, and an onward conveyor for onward conveying of the printed products, which have been separately released, to a transfer position from which the printed products can be removed, in step with the cycle, from the infeed system of the subsequent processing machine. The onward conveyor is a continuous-drive belt conveyor or roller conveyor on which the printed products are transported by means of frictional force.
The printed products are released by the arrestor as early as possible so that despite the slip-type transport they arrive in time at the transfer position. The transfer position is defined by an end stop against which the printed products are continuously conveyed by the onward conveyor until such time as they are taken over by the infeed system. In this arrangement, the conveyor belt or the conveyor rollers of the onward conveyor slip underneath the respective printed product, which in the case of sensitive materials results in corresponding marking on the outside of the printed products.
DE 71 25 313 U1 describes an infeed system which in book binding machines is known as a so-called star feeder. The star feeder is rotating roller which rotates intermittently and cyclically, wherein the roller comprises cut-outs that are arranged in a star-shape for accommodating the printed products. The cut-outs are in each case delimited by two surfaces that are arranged at right angles in relation to each other. Star feeders are used for placing upright any printed products that are fed in a flat position. In a star feeder with six segments the printed products are fed to a section which is inclined by 30° relative to horizontal. In this arrangement, one of the two surfaces is used as an end stop, while the second surface is used to lift the printed products from the infeed conveyor. Due to the necessary interpenetration of the infeed conveyor and the star feeder, the star feeder is made from a multitude of discs which are arranged on a common shaft so as to be parallel in relation to each other, wherein individual conveyor belts of the infeed conveyor reach into the interspaces between the discs.
For increased cycle performance, star feeders comprising eight segments have been developed, which star feeders place the printed products from a flat position to the spine or the fore edge cut. The printed products are infed with the above-described infeed conveyor which is associated with the disadvantages mentioned above. Due to the transport time for feeding the printed products into the cut-out of the star feeder having been designed for an arrangement with relatively great slip, the cyclic performance of the infeed system is limited.
From DE 198 10 112 A1 a device for feeding books to a rotary device in step with the working cycle is known, which rotary device comprises a transfer conveyor with a controllable drive. By means of a sensor which is arranged in the infeed region of the transfer conveyor, the front edge of an infed printed product is registered. The deviation (being the difference in travel between the desired position and the actual position) is corrected by the control system in the drive of the transfer conveyor in such a way that the rear edge of the respective printed product is transferred, in a manner synchronous with the cycle, to catches of a conveyor arranged downstream of the transfer conveyor. In this process the respective format length of the printed products is also taken into account. With such drive control systems, a host of different tasks in conveyance systems to be controlled can be performed, wherein additional expenditure as a result of the controllable drives must be taken into account.